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Oracle Migration Workbench - Part 4

At the end of Part Three,
we finished installing SQL Server and created a user account that has access to
the Northwind database. In Part Four, we will go into more detail about SQL
Server and how it compares to Oracle. This part of the series also covers
the setup and preparation to use Oracle Migration Workbench to migrate the
Northwind database from SQL Server to Oracle.

SQL Server versus Oracle

To be more precise, that is
SQL Server 2000 versus Oracle9i. By and large, I believe the supporters of each
product are firmly encamped, that is, they believe theirs is THE database
product and all others pale in comparison. In a segmented market where product
share is widely distributed by platform and type of user, there is no reason to
fault anyone for his or her belief about which product is the best, because "best"
for one person may not be "best" for the other. There is an
historical analogy, which parallels the RDBMS "mine is the best"
mindset, and it has to do with word processing.

If you were on computers in
the late 1980's/early 1990's, you may recall the word processing war among WordStar,
WordPerfect, MultiMate, DisplayWrite and the emerging Microsoft product called
Word. Lotus had something too as I recall. Whichever product you started with,
you tended to stay with it. My favorite was a product named ProWrite, and it
was definitely Off-Broadway in terms of being an actor. Who rules today?
Microsoft Word has become, for all practical purposes, the lingua franca
of the word processing world. One of the top hits on a Google search for MultiMate
is about a cow mating program. Ouch. Not to mention all those brain cells I
stressed trying to remember the 40-plus MultiMate Ctrl-Alt-Shift F-whatever
keystroke combinations to make a document look halfway decent - who would put
up with a program like that in today's world of software?

Part of the purpose of this
series, as far as Oracle DBAs are concerned, is to provide some background for
you about other RDBMS products (MySQL and SQL Server as mentioned, and this may
extend to DB2). For open source, inexpensive database needs for a small web
site, MySQL certainly fills the bill. As a small-to-medium business, the answer
is a bit murky as to which product suits your need. Pricing, performance, ease
of use, and reliability are critical considerations is selecting a product.

If you are coming from the
Oracle world and you take the time and effort to get into some of the features
of SQL Server, you are going to walk away with both of these impressions:

1) "Wow,
I wish Oracle did that."

2) "Gee,
I hope Oracle does that in its next release."

SQL Server's interface and
easily accessible functionality, presented either via GUI-based menus or
supplied by ready-to-use scripts and procedures, is far superior to what Oracle
offers out of the box, and that superiority extends to something you only get
once: a chance to make a first impression. The appearance of SQL Server tools,
by the very nature of its one and only platform, capitalizes on the Windows
look and feel. Oracle, on the other hand, uses Java-based GUI interfaces,
which, without getting into Java's limitations on GUI, just does not have the
same pizzazz as a true Windows-based interface. Then again, you will not see
SQL Server on a UNIX-based platform. The "Which is the better server
platform, Windows or UNIX?" debate is for someone else to moderate.

If you have a firm grasp of
Oracle's architecture, learning SQL Server's setup is a relative breeze. You
know what has to be done or what should take place in Oracle, so your task is
to learn how SQL Server accomplishes the same things. However, there are
several key differences in the "how" department.

A quick overview of the
differences at this point will be helpful. There are plenty of other sources
which cover these differences. A Prentice Hall book titled "Microsoft SQL
Server 2000 Database Administrator's Guide" is one such reference. It
includes a chapter about migrating from Oracle to SQL Server, and you can see
how Microsoft's approach to what makes a database work is similar and different
from Oracle's approach. The documentation which comes with Migration Workbench
includes a side-by-side comparison of these database systems. SQL Server, like
Oracle, runs on ACID. That's "ACID" as in Atomic, Consistent, Isolated,
and Durable. If a database system can't pass the acid test, so to speak, you
cannot be certain about the accuracy and consistency of its data, and without
that, what good is it?